As the solid state drive (SSD) plays an increasingly important role in computer and enterprise storage, there is a correlated increase in importance and reliance on the use of backup power sources, such as capacitors in the form of supercapacitors, to help prevent data loss in the SSD from occurring due to a power outage or power loss. When a power outage or power loss occurs for a host device, such as a computer, with an SSD, the energy stored by a supercapacitor provides backup power to ensure that all pending commands are successfully completed by the SSD, all critical data is saved, and the SSD can shut down properly. The time during which the supercapacitor provides backup power is often referred to as the hold-up time. Absent the supercapacitor, critical data that is lost during the power outage or power loss may result in unrecoverable errors once power is restored.
Typically, SSDs that are equipped with a supercapacitor as a backup power source keep the voltage stored within the supercapacitor ring-fenced, not using it for any other purpose than to provide backup power during a power outage or power loss event. During a power outage or power loss event, the SSD switches the power source to the supercapacitor, causing a drop in power efficiency due to the increased voltage conversion losses when using a supercapacitor as the main power supply. The reduction in power efficiency as a result of the switch to the supercapacitor reduces the amount of time the SSD can remain powered by the supercapacitor. Thus, in order to keep the SSD powered for a sufficient amount of time to ensure that all pending commands are successfully completed by the SSD and all critical data is saved, a supercapacitor with a larger capacity is required, thereby increasing the cost and possibly the physical size of the SSD.
There is, therefore, an unmet demand for SSDs with backup supercapacitors having improved power efficiency during a power loss or power failure event.